Alkali-soluble polymeric carboxy ester lactones



'nited States Patent \LKALI-SOLUBLE POLYMERIC CARBOXY ESTER LACTONES .s M. Minsk and Edward I. Abel, signors to Eastman Kodak Company, corporation of New Jersey Drawing. Filed Aug. 26, 1963, Ser. No.

7 Claims. (Cl. 260-485) Rochester, N.Y., Rochester, N.Y.,

CHsCO O Interpolymers of alpha-beta-dicarboxy-lic acids or an- :lrides and vinyl esters have been modified by reaction :h a monohydric alcohol and an acid catalyst whereby :y were deacylated and lactonized and simultaneously e carboxyl was esterified with a monohydric alcohol.

.e resulting lactone esters are insoluble in water and thout hydrolysis treatment are insoluble in alkali.

iese compounds and their preparation have been deribed in McNally and Van Dyke U.S. Patent No. 2,-

For some applications such as developer removable .ckings or stripping layers for photographic film, it is .sirable to have highly flexible materials which are war insoluble but which will dissolve in aqueous alkaline tlutions particularly in weak bases on the order of dite aqueous solutions of sodium bicarbonate. A meth- 1 of preparing such materials in a homogenous proceire has been disclosed in US. Patent No. 3,007,901 of linsk which procedure is characterized by the use of monohydric hydroxy acid.

One object of our invention is to provide a method f making carboxy lactone polymers which exhibit soibility in dilute alkali suitable for alkali removable coatigs particularly for photographic products. Another bject of our invention is to provide a method for modiying the physical and chemical characteristics of inter- |olymers of unsaturated alpha-beta-dicarboxylic acids or heir anhydrides and vinyl organic acid esters in which he use of a monohydric hydroxy acid is avoided without mpairing the excellent solubility of the product. Other )bjects of our invention will appear herein.

We have found that products having good alkali solunility are obtained by modifying heteropolymers of an anhydride of an unsaturated alpha-beta-dicarboxylic acid and a vinyl organic acid ester, having an inherent viscosity of no more than 0.30, with a reaction mixture composed of water, monohydric alcohol and an acid catalyst in which the water is present in a molar ratio of at least 1.811 to the monohydric alcohol or without any alcohol present. By the modification of the lower viscosity heteropolymers in this manner, products are obtained having good and useful properties for the application of alkali soluble coatings to photographic products which coatings are readily removable by alkaline solutions including those weakly alkaline such as photographic developers or the like.

In preparing products in accordance with our invention we employ as the starting material a heteropolymer 3,260,706 Patented July 12, 1966 "ice of an unsaturated alpha-beta-dicarboxylic acid or its anhydride and a vinyl organic acid ester which has an inherent viscosity measured in acetone at a concentration of 0.25 gram per 100 ml. of solution of not more than 0.30. The alpha-beta-dicarboxylic acid or anhydride may be maleic, itaconic, citraconic, dimethylmaleic or the like. The vinyl organic acid ester may be the vinyl ester of any commonly used organic acid such as vinyl acetate, vinyl pr-opionate, vinyl benzoate or the like.

Products prepared from intermediates with an inherent viscosity greater than 0.30 invariably show anomolous viscosity behavior either as the free acid or as the sodium salt due to cross-linking occurring during the reaction. If a viscosity high enough is used, the degree of crosslinking reaches a level sufficiently high to make the prodduct useless.

In its broadest aspects our invention involves reacting upon a heteropolymer, as described, With a reaction mixture comprising a substantial amount of water and with or without added monohydric alcohol under the influence of an acid catalyst which reaction introduces sufiicient carboxyl groups into the interpolymer to provide a carboxyl content of from 12% up to theoretical (40.8%) calculated as maleic acid depending upon the amount of alcohol added and the water to alcohol ratio. The ratio in moles of water to monohydric alcohol in the reaction mixture should be at least 1.811, and preferably at least 5: 1. In some cases no monohydric alcohol is used. The reaction should be carried out in a reaction mixture in which the liquid is at least 3 times the amount of heteropolyrner used. Where no monohydric alcohol is used a considerable proportion of water is used such as at least 5 parts of water per part of heteropolymer by weight.

To promote the reaction it is desirable that the mixture be maintained at an elevated temperature such as that provided by a steam bath for a considerable time. Alternately, an enclosed vessel or autoclave may be employed if desired. By providing a molar proportion of water greatly in excess of the molar proportion of alcohol, a considerable content of carboxy groups is introduced into the heteropoly-rner to obtain a product having sufficient carboxyl content to assure alkali solubility.

The products obtained in accordance with our invention are lactones of resinous heteropolymers of vinyl alcohol and unsaturated alpha-beta-dicarboxylic acids, optimally but not necessarily partially esterified by a monohydric alcohol. They are readily soluble and hence are adapted in the form of their solutions in organic solvents for use for supplying coatings such as backings or the like to photographic products which coatings because of their solubility in aqueous alkaline solutions such as developers are readily removable upon processing of the photographic film or other products coated therewith.

Because of their excellent solubility, our products may be readily converted to their sodium salts by the methods given in pending US. application Serial No. 145,435 now Patent Number 3,169,946 (Minsk) to yield smooth readily flowable solutions. I

The following example illustrates the preparation of a heteropolymer of maleic anhydride and vinyl acetate having an inherent viscosity measured in acetone at a concentration of 0.25 gram per 100 ml. of no more than 0.30.

Example In a 12 liter flask equipped with a reflux condenser and stirrer the following materials were placed: 860 grams of vinyl acetate, 980 grams of maleic anhydride, 5520 ml. of acetone, 27.6 grams of benzoyl peroxide. .The mass was heated at C. overnight (16-18 hours) and the dope obtained was diluted with acetone to precipitation viscosity and the mass was precipitated in 20-25 gallons of agitated distilled water. The vinyl acetate-maleic anhydride heteropolymer thus obtained quid, water washed several times, centrifuged and dried. The heteropolymer thus obtained Other well known esters and unsaturated alpha-beta-dicarboxylic acids can be prepared in teri als for processes was separated *from the li had an inherent viscosity of 0.23. interpolymers of vinyl organic acid similar manner for use as starting ma in accordance with our invention.

The following examples illustrate our invention.

Example 1 Into a 2 liter flask equipped with reflux condenser and stirrer were placed 200 grams of vinyl acetate-maleic 'anhydride interpolymer (inherent viscosity 0.29) 600 ml. of distilled *water and 70 ml. of n-butyl alcohol. The mixture was gently stirred for 12 hours and a clear solution was obtained. 68 ml. of concentrated sulfuric acid was then added dropwise and the mass was heated on a steam bath 'for 1 /2 hours. The formation of solid base. Direct titrati with N/Z NaOH to carboxyl equilavent is equivalent to a c acid, of 18.2%.

In the following table the above procedure correspo to Number 12. Other preparations were carried out like manner but using the proportions indicated in table as follows:

Intermediate Analysis n-Butyl Molar Ratio Water Alcohol 01" Water/ Inherent (mL) (1111.) Alcohol 1 N N aOH Percent (G.) Viscosity (ml./g.) Carboxyl material was noted. The heating was continued for 18 hours. The solid which formed 'was separated from the liquid and was kneaded in a Werner-Pfleiderer mill in repeated changes of water to reduce acidity and to harden and break up the polymer.

After the carboxy ester lactone thus obtained was completely freed of acid it was dried in a 40 oven overnight to obtain a yield of 150 grams. Titration indicated carboxyl equivalent to 5.18 ml. of n or a carboxyl content in terms of maleic acid of 30%. This preparation and the product are designated as Number 3 in the accompanying table. Other preparations were carried out in like manner varying the molar ratio of water to butyl alcohol as indicated.

used and the results obtained were as follows:

ormal NaOH per gram, 4-

The proportions 1 aleic A( The products of the various examples were employc as backings for photographic film. The coatings we:

40 found to have good adherence and to be removable Whe the film was processed in alkaline developer solution Example 3 maleic acid, of 31.7%.

nterrucdiate Analysis n-Bntyl Molar Ratio Water Alcohol of Water/ Inherent (mL) (ml) Alcohol 1 N N aOH Percent (GJ Viscosity (mL/g.) Carboxyl as Maleic Acid Example 2 a smooth dope was 75 Example 4 of the polymer in 70 ml. of concentrated tic acid. The mixture was heated on a steam bath .ight. After cooling, the solid material formed was ated, washed free from mineral acid and dried. tion of the lactone obtained indicated carboxyl 'alent to 6.6 ml. of normal NaOH per gram or in s of maleic acid the carboxyl content was 38.3%.

iis example was repeated using different proportions inherent viscosities. The proportions and viscosities and the results obtained compared with theoretical DXyl are given in the following table, the procedures ribed in Example 4 being that designated as Number 1 the table.

Intermediate Analysis Water (ml) (GJ Inherent 1 N NaOH Percent Viscosity (ml./g.) Oarboxyl as Maleic Acid .heoretical.

Ve claim:

.. A method of preparing alkali soluble polymeric car- :y ester lactones which comprises reacting one part a soluble interpolymer of a compound selected from group consisitng of the unsaturated alpha-beta-dicarrylic acids and anhydrides and a vinyl organic ester ring an inherent viscosity in acetone at a concentration 0.25 gram per 100 ml. of solution of not more than '0 with at least 5 parts of a liquid free of monohydroxy .d composed of one molar proportion of water and 0.59 molar proportions of a lower monohydric alcohol gether with a mineral acid catalyst having a strength the order of sulfuric acid at above room temperature itil lactonization of the polymer has occurred.

2. A method of making alkali soluble polymeric car- )xy ester lactones which comprises reacting one part f a soluble interpolymer of a compound selected from .e group consisitng of the unsaturated alpha-betadicar- )Xylic acids and anhydrides and a vinyl organic ester hich has an inherent viscosity in acetone at a concenation of 0.25 gram per 100 ml. of solution of not more lan 0.30 with at least 5 parts of a liquid free of monoydroxy acid composed of water and alcohol in which 1e water is present in a molar ratio of at least 1.8:1 )gether with a mineral acid catalyst having a strength n the order of sulfuric acid at above room temperature 3 a point at which the polymer has been lactonized.

3. A method of preparing alkali soluble polymeric car- )OXY ester lactones which comprises reacting one part )f maleic anhydride-vinyl acetate interpolymer having ll'l inherent viscosity in acetone at a concentration of 6 0.25 gram per 100ml. of solution of not more than 0.30 with at least 5 parts of a liquid free of monohydroxy acid composed of one molar proportion of water and 0-059 molar proportions of a lower monohydric alcohol with a mineral acid catalyst having a strength on the order of sulfuric acid at above room temperature to a point at which the vinyl acetate-maleic anhydride has been lactonized.

4. A method of preparing alkali soluble polymeric carboxy ester lactones which comprises reacting 200 parts by weight of vinyl acetate-maleic anhydride interpolymer having an inherent viscosity in acetone at a concentration of 0.25 gram per 100 ml. of solution of not more than 0.30 with a liquid free of monohydroxy acid composed of 600 parts by volume of Water and parts by volume of normal butyl alcohol with sulfuric acid catalyst at above room temperature to a point at which the polymer has been lac-tonized.

5. A method of preparing alkali soluble polymeric carboXy ester lactones which comprises reacting 200 parts by weight of a vinyl acetate-maleic anhydride heteropolymer having an inherent viscosity in acetone at a concentration of 0.25 gram per 100 ml. of solution of not more than 0.30 with a liquid free of monohydroxy acid composed of 460 parts by volume of water and 500 parts by volume of normal propyl alcohol with sulfuric acid catalyst at above room temperature to a point at which the polymer has been lactonized.

6. A method'of preparing alkali soluble polymeric carboxy ester lactones which comprises reacting 200 parts by weight of a vinyl acetate-maleic anhy-dride heretopolymer having an inherent viscosity in acetone at a concentration of 0.25 gram per 100 ml. of solution of not more than 0.30 with a liquid free of monohydroxy acid composed of '600 parts by volume of water and parts by volume of benzyl alcohol with sulfuric acid catalyst at above room temperature to a point at which the polymer has been lactonized.

7. A method of preparing alkali soluble polymeric carboxy ester lactones which comprises reacting one part of a vinyl acetate-maleic anhydride heteropolymer having an inherent viscosity in acetone at a concentration of 0.25 gram per ml. of solution of not more than 0.30 with a liquid free of monohydroxy acid essentially consisting of water and sulfuric acid catalyst at above room temperature to a point at which the polymer has been lactonized.

References Cited by the Examiner UNITED STATES PATENTS 2,306,071 12/1942. McNalily 26078.5

JOSEPH L. SCHOFER, Primary Examiner. L. WOLF, Assistant Examiner. 

1. A METHOD OF PREPARING ALKALI SOLUBLE POLYMERIC CARBOXY ESTER LACTONES WHICH COMPRISES REACTING ON PART OF A SOLUBLE INTERPOLYMER OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF THE UNSATURATED ALPHA-BETA-DICARBOXYLIC ACIDS AND ANHYDRIDES AND A VINYL ORGANIC ESTER HAVING AN INHERENT VISCOSITY IN ACETONE AT A CONCENTRATION OF 0.25 GRAM PER 100 ML. OF SOLUTION OF NOT MORE THAN 0.30 WITH AT LEAST 5 PARTS OF A LIQUID FREE OF MONOHYDROXY ACID COMPOSED OF ONE MOLAR PROPORTION OF WATER AND 0.059 MOLAR PROPORTIONS OF A LOWER MONOHYDRC ALCOHOL TOGETHER WITH A MINERAL ACID CATALYST HAVING A STRENGTH ON THE ORDER OF SULFURIC ACID AT ABOVE ROOM TEMPERATURE UNTIL LACTONIZATION OF THE POLYMER HAS OCCURRED. 